Boarding walkways for passengers used in airports are generally formed by a rotunda with a fixed height which is connected to the boarding gate of the airport, by a cabin which is connected to the door for accessing the aircraft, and by a tunnel running between the rotunda and cabin and forming the movement path for the passengers to access the aircraft from the airport.
The height of the cabin depends on the type of plane to which the walkway is connected. Since the height of the cabin can vary and the height of the rotunda is fixed, the inclination of the tunnel connecting the cabin and the rotunda will vary, depending on the plane to which the walkway is connected, the tunnel being able to run with an upward or downward inclination from the rotunda. For this reason, there must be a connection between the rotunda with a fixed height and the tunnel with a variable inclination which allows varying the inclination of said tunnel and which furthermore offers a good closure in order to isolate the users from the exterior.
In traditional boarding walkways this connection is carried out by means of a fixed device always adopting the same configuration for any service position of the walkway, whereby the volume occupied by this device remains constant, making the transport and handling operations of this device difficult and more expensive and above all creating a certain resistance to the movements of the tunnel.
Another existing system for this connection consists of elastic or flexible bellows which are adapted by being extended and compressed to each service position of the walkway. The problem of the elastic closures is their short life, which forces frequent replacements and repairs.